<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        document.writeln("欢迎你,学习JavaScript脚本语言");
    </script>
</head>
<body>
    <script>
        document.writeln("欢迎你,学习JavaScript脚本语言");
    </script>
    <div>
        <button onclick="alert('欢迎你,学习JavaScript脚本语言')">点我</button>
    </div>
</body>
</html>